Epidurals may make labor longer than originally thought: study

NEW YORK (Reuters Health) - While a shot to relieve labor
pains is known to increase the time it takes for women to
deliver babies, a new study says the increase may be longer than
originally thought.

Researchers found some women who received epidural
anesthesia during labor took more than two hours longer to
deliver their child, compared to women who didn't get the pain
reliever.

"The effect of epidural can be longer than we think and as
long as the baby looks good and the women are making progress,
we don't necessarily have to intervene (and perform a Cesarean
section) based on the passage of time," Dr. Yvonne Cheng told
Reuters Health.

She is the study's lead author and a specialist in
maternal-fetal medicine at the University of California, San
Francisco.

Cesarean sections, or c-sections, are now used for about one
of every three births in the U.S., according to the Centers for
Disease Control and Prevention. That's about 50 percent more
than in the mid-1990s.

C-sections come with longer hospital stays and extra risks
for mothers and babies.

Cheng and her colleagues write in Obstetrics and Gynecology
that two common reasons for performing c-sections are that it
appears labor has slowed and that the baby is not progressing
through the birth canal.

Traditionally, doctors are taught that women who receive
epidural anesthesia will take about an extra hour to complete
the second stage of labor, which is the pushing part.

But the researchers write that it's unclear where the data
for what's considered a "normal" labor came from and that the
extra hour of labor is an average.

For the new study, they compared data from over 42,000 women
who delivered their children at the University of California,
San Francisco between 1976 and 2008. About half of the women
received epidural anesthesia and the other half did not.

Specifically, the researchers were looking at the length of
the second stage of labor at the 95th percentile, which is an
extreme. That means 19 out of 20 women would complete that stage
of labor within that time.

For women who had never had a child before and were in the
95th percentile for length of labor, the second stage took about
three hours and 20 minutes to complete without anesthesia and
five hours and 40 minutes with the shot.

Women who previously had a child, who usually have shorter
labors to begin with, took about an hour and 20 minutes to
complete the second stage of labor without anesthesia at the
95th percentile. That compared to four hours and 15 minutes with
an epidural.

Overall, the researchers found the second stage of labor
took about two hours longer at the 95th percentile when women
got an epidural.

For women who have a more typical delivery, the epidural
probably adds less time, Dr. Karin Fox said. "It's probably
difficult to know for each individual patient," she told Reuters
Health.

Fox is a specialist in maternal-fetal medicine at the Baylor
College of Medicine and Texas Children's Hospital in Houston.
She was not involved with the study.

While she said the results are not surprising, there may be
reasons besides the epidural why some women's labors last
longer.

She also said women shouldn't stay away from epidural
anesthesia just because it will prolong labor. "There are many
reasons for having an epidural," she said.

Dr. Christopher Glantz cautioned that although the health of
babies in the epidural and non-epidural groups was similar,
mothers tended to have more complications if they had longer
labors.

Glantz was not involved with the study but is a high-risk
pregnancy specialist at the University of Rochester Medical
Center in New York.

"It would appear that the upper limit of what can be
tolerated is greater than what was previously thought, which
takes away some of the impetus to intervene (with c-section) in
what appears to be a premature fashion," he said.

Cheng and her colleagues write that while doctors should not
only rely on this paper to establish how long labors may last,
these findings and previous research suggest current definitions
are not sufficient.

"All the experts in the field should get together to look at
the evidence that's out there and come up with informed
definitions," Cheng said.